Internal combustion engine



,www

Filed July 2o, Y1952 NUUEHDUSE Patented Sept. 17, 1935 UNITED STATES Y2,014,659 INTERNAL CoMBUsTIoN ENGINE Alfred Moorhousc, Detroit, Mich.,assignor to Packard Motor Car Company, Detroit, Mich., a corporation ofMichigan v Application July 20, 193,2, Serial No. 623,506v

13 Claims.

This invention relates to internal combustion engines and particularlyto the valve operating mechanism thereof.

f The invention is in some respects an improvement upon the valvemechanism shown in British Patent bld-289,468, and U. S. patentapplicationl to Edwin Storey, Ser. No. 574,795, filed November 13, 1931.In said British patent and in said application there is described avalve mechanism for internal combustion engines in which the rocker armsare provided with a takeup mechanism to compensate for expansion andcontraction due tol temperature variations. In

the British patent the take-up device is mounted 15 below the pivot ofthe rocker arm and the piston oi the device presses upwardly, thusleaving the cylinder of the device open at its upper` end so that anyair in the device may escape upwardly Yaround the piston. VThere is aspring pressed valve inthe movable, piston.

In the Storey application the take-up device is mounted above the pivotand the piston presses downwardly, the upper end of the cylinder beingclosed except for a spring operated valve.

125 Whilethe British patent indicates that its spring pressedv valvewill be opened by the vacuum created by the upward movement of thepiston, it is found in practice and it is recognized by Storey that acontributing factor to the opening of this valve is the inertia of theparts and that the sudden movement of the piston causes the Vopening ofthe valve to permit escape of air oriniiow of oil.

This matter ofV escape of air from'the working 535 parts of theVcylinder is of utmost importance because if air is trapped below thepistonthe valve mechanism will not operate quietly since the air will becompressed instead of forming a solid wall and the eccentric mountingwill then cause "40 a clearance between the rocker arm and the enginevalve. Hence the necessity for providing means for completelyeliminating the air from side of the center line oi the engine and it isunthe high pressure space of the device.

It is one of the objects of the present invention "145 to.improve uponthe devices of the British patent and the Storey application,particularly in this matter of eliminating the air from the highpressure chamber of the device.

It is an object of the invention that the device T shallrnot only haveits valve at the upper part of wardly from the upper part of the highpressure chamber so that the air in the device will be (Cl. 12S-90)forced out at that point when the device is under compression.

Another object of the invention is to provide for circulation of the oilinthe device itself, downwardly through the spring pressed valve into 5the high pressure chamber, and upwardly from the upper end of thecompression chamber into a chamber at the upper part of the device whichis open to the atmosphere. Thus the air will l escape from the oil andafter all of the air has 10 been -eliminated from it this same airlessoil will continue to be use d in the device and thus improve itsoperation.

Other objects of the invention will appear from the followingdescription taken in connection`15 with the drawing, which forms a partof this specication, and in which the figure is a vertical transvers-esection through the central portion of a V-type internal combustionengine embodying the invention. 20

Referring to the drawing I represents generally a cylinder block castingwhich may or may not be a single casting, as shown in the drawing.Mounted in bearings II in the casting is a cam shaft 52 and above thecam shaft is an openingl25 I3 in which is mounted a casting or supportI4 which supports the valve operating mechanism. One of the rocker armsfor the valve mechanism is indicated at I5, and this rocker arm isprovided with a roller I6 which contacts with a cam 30 on the cam shaftI2, and the other end of the arm has a contact point Il operating on theend of the engine valve I8. The latter valve is closed by a spring I8.`The rocker arm is mounted upon an eccentric sleeve I9 on a pin 29,which.` 35

,sleeveV hask a lever arm 2l extending radially therefrom for thepurpose of rotating it slightly on the pin 2l) and thereby adjusting theclearance between the roller I S and the cam shaft and the point I'I ofthe rocker arm and the valve 40 I 8. There is a similar pin 20 on theopposite derstood that similar rocker arms are mounted thereon, thereusually being one rocker arm and take-up mechanism rfor each enginevalve. 45

Mounted above the lever arm 2| is the take-up device of this invention.It is indicated generally at A and it comprises an inverted cylinder 25which may be formed directly inthe casting o1' support I4 as shown inthe drawing. This is a 50 stationary cylinder and `it is integrallyclosed vat its upper end except for an opening 26 into which is tted thestub end 2l of a piston 28. This is a stationary piston and in eiectforms a part of the cylinder 25. It is somewhat smaller than the 55interior diameter of the cylinder 25 and it abuts against the closedupper end of that cylinder.

The piston 28 is in two parts for convenience in manufacture andassembly, the parts being indicated at 29 and 38, but these parts remaintogether after the device is assembled and there is no relative movementbetween them. The interior of the piston 28 is open to the interior ofthe cylinder 25 at its upper end by reason of passages 3|, and thepiston 28 has its lower end closed except for a passage or opening 32which is closed by a spring pressed valve 33, the Valve openingdownwardly and being held to its seat by a light spring 34. The valvestem 35 of the valve 33 extends upwardly through an opening 36 in theupper end of the stub end of the piston, the iit being loose so that thevalve may readily find its seat. The lower end of the spring 34 restsagainst the end of the piston 28 and the upper end operates against aflanged sleeve 31 held on the valve stem 35 by a split ring 38 in agroove in the Valve stem.

A movable hollow cylinder 40, which may be called the working cylinder,extends up into the stationary cylinder 25 and surrounds the lower part30 of the piston 28, the t between the outer wall of the piston part 30and the inner wall of the cylinder 4D being such that leakage may occurunder high pressure and thus form a dashpot as liquid is expelled fromthe cylinder under pressure. The fit between the outer surface of themovable cylinder 40 and the inner surface of the stationary cylinder 25is fairly close so that there may be very little leakage and thestationary cylinder may form an adequate guide for the movable cylinder.

The lower end of the cylinder 40 is formed with an extension or nose 4|which rests against the lever arm 2| of the sleeve I9, and a spring 42between the lower end of the piston 28 and the movable sleeve tends toconstantly press the latter against the lever arm 2|, for the purposeabove described.

The space between the lower end of the piston 28 and the head of thecylinder 40 is a high pressure chamber indicated at 43, the highpressure being caused by the operation of the valve mechanism in whichthe cam tends to rock the rocker arm |5 against the valve spring I8',thus constantly pushing upwardly on the lever arm 2|. As the rocker arm|5 drops off of the cam and the Valve |8 is closed, the spring 42returns the cylinder 40 to its original position and takes up theclearance at either end of the rocker arm. During this latter movement,if the liquid within the high pressure chamber 43 has been pressed outto any extent between the cylinder 40 and the piston 28, it will bedrawn back in again by reason of the partial vacuum created therein, thevalve 33 opening to permit the liquid to again enter the high pressurechamber.

But it is found that the partial vacuum created is not always suiiicientto open the valve 33 and consequently a small cylinder 44 is formedWithin the cylinder 4D, and an extension 45 is provided on the lower endof the Valve 33, and a piston 46 forms the lower end of said extension45. This piston 46 is just slightly smaller than the inner diameter ofthe cylinder 44 but the iit is suiiiciently close so that when thecylinder 44 is suddenly pushed outwardly by the spring 42 it will carrywith it the piston 46 and consequently open the valve 33, thusfacilitating the flow of oil back to the high compression chamber.V Butthe movement of the cylinder 40 is brief and when it comes to a stop thespring 34 of the valve 33 returns the valve 33 to its seat by reason ofthe oil passing around the piston 46. Also, by reason of this relativelyloose fit of the piston 46 in the cylinder 44, and the loose lit of theupper end of the valve stem 35 in the opening 36, the valve 33 ispermitted to find its seat and thereby make a good close fit to preventleakage of oil at that point.

With the valve take-up device A substantially filled with oil as will behereinafter described, it

will be seen that the escape of oil from the high pressure chamber 43 isfrom the extreme upper end of that chamber around the piston part 30 andbetween the latter and the inner wall of the movable cylinder 40. Thusif there is any air in the oil it will readily escape under the highpressure referred to, whereas, if the escape for oil was at the lowerpart of the chamber when the chamber was under high pressure, the airwould remain at the upper end of the chamber and would not escape withthe oil. The entrance of oil to the high pressure chamber is at thebottom of the piston part 30 where there is not likely to be much air inthe oil, this entrance being through the opening 32 which is controlledby the valve 33. Since this valve 33 is open only during the time of lowpressure or partial vacuum in the chamber 43, this passage is of novalue in permitting the escape of air.

At the lower part of the drawing it will be observed that there is anoil intake passage at 50 and it will be understood that oil underpressure is supplied to this passage by any suitable means, not shown.In tris passage 58 is a metering pin 5| which is made slightly smallerthan the passage to permit a definite amount of oil to pass. A spring 52causes a movement of the pin 5| with the fluctuations in the pressure ofoil against it, thus keeping the passage clean. The oil is led to agroove 53 surrounding the bearing and grooves Eil, shown in dotted linesin the bearing and in the cam shaft |2, lead the oil to the interior ofthe cam shaft where it is carried to other bearings. A conduit 55 withbranches 56 carry the oil from the groove 53 to the hollow pins 20 uponwhich the eccentric sleeves I9 are mounted. This provides lubricationfor the sleeves and the rocker arms. A conduit 51 adjacent each of thecylinders 25 carries the oil upwardly to a pocket 58 at the tops of thecylinders. From this pocket openings 59 lead into the upper part of eachof the cylinders 25. Thus the oil fed to the pins 20 is carried upwardlythrough the conduits 51 and delivered to the upper end of the cylinder25 so that the latter is always filled with oil. The overflow from thepocket 58 falls back into the crank case of the engine and isrecirculated.

While I have herein described in some detail a. specific embodiment ofmy invention, which I deem to be new and advantageous and mayspecifically claim, I do not desire it to be understood that myinvention is limited to the exact details of the construction, as itwill be apparent that changes may be made therein without departing fromthe spirit or scope of my invention.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A valve take-up mechanism comprising a lever arm, a support, astationary piston extending downwardly from the support, a springpressed cylinder movable on said piston and closed at its lower end,said cylinder operating on said lever arm, said piston having a port inits head, a spring closed valve for said port, and means operated by themovable cylinder for controlling the valve action.

2. A valve take-up mechanism comprising a piston having a ported head atits lower end, a spring closed valve for said port, a spring pressedcylinder slidably mounted on said piston and means operated by themovable cylinder for controlling the valve action.

3. A valve take-up mechanism comprising a piston having a ported head atits lower end, a spring closed valve for said port, a spring pressedcylinder slidably mounted on said piston, and means including ahydraulic connection between said valve and said cylinder forcontrolling the operation of said valve.

4. A valve take-up mechanism comprising a lever arm, an invertedcylinder mounted adjacent thereto, a downwardly extending piston withinsaid cylinder and stationary with relation thereto, a second cylinderwithin the rst cylinder and operating upon said piston with leakageclearance between the piston and second cylinder, said second cylinderhaving a closed lower head operating on said lever arm, a spring betweenthe piston and second cylinder, and a valved passage means in the pistonhead.

5. A valve take-up mechanism comprising a lever arm, an invertedcylinder mounted adjacent thereto, a downwardly extending piston, asecond cylinder within the first cylinder and operating upon saidpiston, a valved passage means in the piston, and means including ahydraulic device forming a connection between said valve and said secondcylinder.

6. A valve take-up mechanism comprising a lever arm, a cylinder having ahead operating against said arm, a stationary piston extendingdownwardly into said cylinder and having a port at its lower end, avalve for said port, and means including a hydraulic device forming aconnection between said valve and said cylinder.

'7. A valve take-up mechanism comprising an inverted cylinder, a secondcylinder moving in the first cylinder, a piston stationary with relationto' the first cylinder and comprising two parts telescoped together, oneof said parts extending into ,the movable cylinder and the other of saidparts abutting against the closed end of the stationary cylinder andmeans for supplying oil to both cylinders.

8. A valve take-up mechanism comprising a stationary member having aport therein, a cylinder sliding on said member, a valve for said port,a spring for closing said valve, said valve having a hydraulicconnection with the cylinder and having at its opposite end a stemguided by said member, said connection and said stem guiding 5 meansbeing sufficiently loose to permit free seating of the valve.

9. A valve take-up mechanism comprising a stationary cylindersubstantially closed at its upper end and open at its lower end, asecond cylinder operating in the rst cylinder and having a closed lowerend, a stationary piston abutting against the closed end of the firstcylinder and extending inside the second cylinder, and means forsupplying oil to the stationary cylinder below its closed head and tothe second cylinder below the stationary piston.

10. In a valve take-up mechanism, the combination of a supportingcylinder open at its lower end, a working cylinder within the rstcylinder and extending Yoperatively beyond the lower end of the firstcylinder, means within the cylinders comprising a high pressure chamberwith air and oil escape at the top of said chamber only, and valvedpassage means in connection with said high pressure chamber.

11. In a valve take-up mechanism, the combination of a supportingcylinder open at its lower end, a working cylinder within the firstcylinder and extending operatively beyond the lower end of the rstcylinder, means within the cylinders comprising a high pressure chamberwith air and oil escape at the top of said chamber only, valved passagemeans in connection with said high pressure chamber, and means includinga hydraulic device forming a connection between the valve of saidpassage means and said working cylinder.

l2. A valve take-up mechanism comprising a stationary hollow piston, aworking cylinder surrounding said piston and spring pressed relativethereto, a valved passage means between the interior of the cylinder andthe interior of the piston and means controlling the valve action.

13. A valve take-up mechanism comprising a stationary hollow piston, aworking cylinder surrounding said piston and spring pressed relativethereto, a valved passage means between the interior of the cylinder andthe interior of the piston, and means including a hydraulic deviceforming a connection between the valve of said passage means and saidcylinder.

ALFRED MOORHOUSE.

